4% of Hikikomori cases had ever experienced at least one psychiatric disorder, and the onset of the psychiatric disorder preceded the state of Hikikomori in 35% of cases. They also reported that 0.5% of the community population had at least one child currently experiencing Hikikomori. These results indicate that approximately 232,000 people are currently

suffering from the Hikikomori state in Japan [6]. selleck chemicals Although the survey did not investigate the prevalence of pervasive developmental disorders (PDDs) including autistic and Asperger disorders as well as pervasive developmental disorders not otherwise specified (PDD-NOS), recent clinical fields have noted that many individuals with PDDs and psychiatric comorbidities such as mood, anxiety, and sleep disorders were included among Hikikomori cases. As PDDs are widespread abnormalities of social interactions and communication, as well as severely restricted interests and highly repetitive behavior (DSM-IV-TR) [7], individuals with Pexidartinib datasheet PDDs, and especially those with high-functioning PDDs, face many problems in their daily lives if they do not receive support and

understanding. Additionally, individuals with severe social maladjustment tend to withdraw from social situations and activity. According to self-reports, they tend to sleep and wake at irregular or inappropriate times and to suffer from sleep disorders by nature (see ‘Circadian rhythm sleep disorder in individuals with PDDs’), and they tend to sleep at extreme late night or during the day, as previously reported in school refusal children and adolescents [8], while experiencing social maladjustment and Hikikomori states. Kuppermann et al. (1995) conducted a survey of the daytime consequences and correlates of sleep problems and found them to be associated with mental health problems; physical problems

such as headaches, neck, back, or muscle pain and gastrointestinal problems; and lower quality of life such as poorer self-rated health, less energy, Methane monooxygenase worse cognitive functioning and lower job performance [9]. Several studies have also reported that irregular sleep–wake rhythms were associated with deactivated daytime functions and poor emotional states [10], [11] and [12]. Lower levels of dominance, sociability, self-acceptance, self-control, achievement via conformance, and intellectual efficiency were also observed in habitual irregular sleepers compared with regular sleepers [11]. Self mutilation common in PDDs is increased with emotional problems and oral mutilation includes multiple ulcerations, gingival irritation lesions and autoextracted teeth [13]. Therefore, it is probable that sleep management in PDDs is an important aspect of their oral health because impairments of emotional control might trigger not only self mutilation but also refusals of dental cares, evaluations and treatments.